acpi: unneccessary to scan the PCI bus already scanned

http://bugzilla.kernel.org/show_bug.cgi?id=10124

this change:

      commit 08f1c192


      Author: Muli Ben-Yehuda <muli@il.ibm.com>
      Date:   Sun Jul 22 00:23:39 2007 +0300

         x86-64: introduce struct pci_sysdata to facilitate sharing of ->sysdata

         This patch introduces struct pci_sysdata to x86 and x86-64, and
         converts the existing two users (NUMA, Calgary) to use it.

         This lays the groundwork for having other users of sysdata, such as
         the PCI domains work.

         The Calgary bits are tested, the NUMA bits just look ok.

replaces pcibios_scan_root by pci_scan_bus_parented...

but in pcibios_scan_root we have a check about scanned busses.

Cc: <yakui.zhao@intel.com>
Cc: Stian Jordet <stian@jordet.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Yinghai Lu" <yhlu.kernel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>